Find a combination of numbers that adds up to ten and try to earn a high score.

Big Top 10, from Bight Games, is surprisingly fun for a microgame based on kindergarden-level arithmetic. It’ll give you double digits on the brain.

Bravo, old bean!

A jumbled grid of integers stares out of the screen, filled with numbers from -9 to 9. These must be assembled into groups that sum up to exactly 10. A drag of the finger starts adding them together, while a counter keeps track of how close you are to the magic number.

Each game of Big Top 10 starts with a minute on the clock, but can last many times longer than that, since making 10s puts a little time back. The idea is to strive for the high score, but there’s a catch–the longer the number chain you find, the bigger score bonus you get.

It’s a case of risk vs. reward. Do you want to tread water by adding 4s to 6s, or would you prefer to spend time hunting for board-spanning combos that score mega points? The situation is complicated by powerups that blow up nearby spaces, freeze the clock, and shrink the board’s numbers when included in a combo.

Big Top 10 is a simple yet addicting game with a jaunty circus theme (the achievements are presented by an old-timey strongman striking weird poses) and a WiFi versus mode. Although we’d like to see online high scores too, it’s a decent use of a buck.

Canadian developer Bight Games ventured south of the border to WWDC with three new games to show off, all of which are being published by Sonic Boom on or around June 18th: Puzzlings, Kill All Bugs!, and Big Top 10. We’ve got impressions and video after the jump.

We’ll start with the least expensive app, Big Top 10, which will retail for 99 cents. This is a number game played on a grid; the object is to swipe across numbers with your finger until they sum up to 10. The longer the number chain, the bigger your bonus multiplier.

It’s a simple concept, but it works well. There are negative numbers to take into account, as well as powerups that blow up big chunks of the board or freeze your clock. The game has an old-timey Big Top look and feel–circus music included–and scads of achievements to unlock. It looks like it could end up as a go-to app for killing time.

Next up is Kill All Bugs!, a whimsical tower defense game with a 50s B-movie theme. Giant, mutated insects are bursting out of the group next to major cities; the Orkin Man won’t cut it, so in comes the military to wage all-out war on the bugs.

In some ways, this game is simpler than competing tower defense titles. There are only a handful of guns–the machine gun, the flamer, and the rocket launcher–as well as stun towers, a power generator for augmenting the power of nearby installations, and a laser fence that sets up a trap for bugs that cross its path.

On the other hand, the game takes considerably more attention from the player than other TD games we’ve seen. After the critters tunnel onto the map, they’ll move in any direction they choose, so you have to be on your toes to reposition towers as necessary.

Plus, some of the towers have special abilities that can be activated with a touch. For instance, the stun tower normally slows enemies down, but if you activate it, it’ll freeze them for a short time. Kill All Bugs! has 21 levels, as well as a survival mode, and we can see that it won’t be easy to earn top marks on all of them.

Bight’s most impressive effort is the $4.99 Puzzlings. “It’s hard to do something new in Match-3,” Bight President and CEO Stuart Duncan told us, “but we think we’ve done it.”

We’ve certainly heard that before, but Puzzlings looks like it’ll back Duncan up. The hook is in the game’s vastly customizable characters (called Puzzlings), which look a bit like the sack people from Little Big Planet.

There are many hundreds of hats, accessories, shirts, and pants to collect throughout the game. You deck your Puzzling out in some new duds, have it strike a pose in front of one of eight backgrounds, and voila! A cool new wallpaper to show off to your buddies.

Oh yeah–the game seems pretty fantastic, too. This is technically Match-3, but Bight has turned the old formula on its head. Instead of switching adjacent blocks, you are allowed to grab any number of blocks in a row and rotate them like a conveyor belt. You can also grab squares of blocks and set them spinning into a new orientation. It feels a bit like playing a psychedelic Rubik’s Cube.

When you fill up a meter by matching blocks, a circular medallion split up into four pieces will drop onto the level. When you reassemble this thing into a circle, you earn a new piece of clothing.

AppSpy takes a look at AG Drive in their latest video review. Giving it top marks and only dinging it for not having multiplayer. If you like “swooshy swoopy futuristic racers” this one might be the one.